Stabilized load-lifting power-actuated truck



Jan. 10, 1950 C. S. BOUCHARD STABILIZED LOAD-LIFTING POWER-ACTUATED TRUCK 6 Sheets-Sheet l Filed June 30, 1948 Jan. l0, 1950 c. s. BOUCHARD STABILIZED LOAD-umm@ PowER-Ac'ruA'rEn TRUCK 6 Sheets-Sheet 2 Filed June 30, 1948 Jan. l0, 1950 c. s. BOUCHARD STABILIZED LOAD-LIF'TING POWER-ACTUATED TRUCK 6 Sheets-Sheet 3 Filed June 30, 1.948

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Jan. l0, 1950 c. s. BOUCHARD STABILIZED LOAD-LIFTING PowER-AcTuATED TRucx Filed June 30, 1.948 6 Sheets-Sheet 4 Caafelo d, 5mm/@1mm JMW Hzadaeys Jan. l0, 1950 c. s. BOUCHARD 2,494,505

STABILIZED LOAD-LIFTING PowER-AcTuATEn TRUCK Filed June so, 194s e sheets-sheet 5 f I; I 48 5|64|| l 619;' 48

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Jan. l0,f 1950 k c. s. BOUCHARD 2,494,505

STABILIZED LOAD-LIFTING- PowER-Ac'rUATED TRUCK Filed June so, 194e 'e sheets-sham e 1521943322034: Ciuuwies if Betania/arid,

Patented Jan. l0, 1950 STABILIZED LOAD-LIFTIN G POWER- ACTUATED TRUCK Charles S. Bouchard, Wellesley, Mass., assignor to Lewis-Shepard Company, Watertown, Mass., a corporation of Massachusetts Application June 30, 1948, Serial No. 36,056

11 Claims. l

This invention relates to improvements in loadlifting power actuated trucks-of the type having a main frame provided with axially alined Widely spaced front wheels and rear steering wheels and a mast fulcrumed on the frame to tilt to and from a vertical -position in front of and spaced from the vertical plane of the axles of the front wheels, a load supporting means mounted upon and movable longitudinally of the mast, and a power unit mounted upon the rear portion of the frame with manually controlled means respectively operable to raise and lower the load supporting means, to tilt the mast and to actuate the wheels to drive the truck. In usual constructions of this type the weight of the frame and the power unit is insuilcient to counterbalance the weight of the mast, the load supporting means and a heavy load carried thereby and in order to overcome this defect the rear portion of the frame is -provided with a counterweight flxedly or usually detachably mounted upon the rear end of the frame or the frame is provided with an integral mass of metal of such thickness as to provide suicient counterbalancing weight to prevent tilting of the truck during the elevation of a heavy load upon the mast.

In the operation of trucks of thistype the mast is tilted rearwardly after loading so as to position the center of gravity of the load above or rearwardly of the fulcrum of the mast during the transportation of the truck and at such height as to minimize the tipping of the truck by centrifugal force when the loaded truck is traveling along a curved path. l

The general object of the invention is to provide a truck of this type of relatively light and economical construction which is stabilized against tipping during the loading of the truck, cushioned againstlateral abrupt tipping during transportation, of relatively short length, and capable of being turned around within approximately the length of the truck in order to pass around abrupt corners of aisles and which can be more conveniently manipulated both as to loading and transportation than trucks heretofore constructed.

One of the objects of the invention is to provide a mast with supporting means adapted to engage the ground or floor when the mast is erected to vertical -position thereby so to support the load as to minimize the necessity for heavy counterbalancing means heretofore required in trucks of this type.

Another object of the invention is to provide means for cushioning lateral swaying movements of the truck during transportation of the load as the truck travels around a curved path.

Another object of the invention is to provide means for driving the truck which will enable it to pass more effectively around abrupt corners of a narrow aisle.

Another object of the invention is to provide a truck of this type having hydraulically operable means for raising and lowering the load supporting means upon a mast and for tilting the mast with continuously operable means for supplying liquid under Ipressure which is selectively operable at all times to raise or lower the load supporting means upon the mast or to tilt the mast to a position in which the load is most effectively located before or during the transportation of the truck.

Another object of the invention is to provide a concentrated mechanism for continuously supplying liquid under pressure to the hydraulically operable mechanism for manipulating the mast and the load supporting means carried thereby and selectively operable to control the driving of the truck forwardly or rearwardly.

A further object of the invention is to provide manually operablemechanism which can be readilygmanipulated by the hands and feet of the operator for controlling the operation of the hydraulic mechanism and for controlling the operation of the driving mechanism and braking mechanism therefor.

Another object of the invention is to' provide a novel frame construction of economical construction in which the major portion of the frame comprises vertical side plates of suitable thickness connected by rear and intermediate girders upon which the power unit is mounted and which is connected at the front end by an axle housing having differential gearing for driving axially alined traction Wheels.

A further object of the invention is to provide rear steering wheel mechanism having vertical spindles which are respectively mounted in brackets upon the vertical side plates of the frame with manually operable mechanism for rotating the spindles in such manner that in combination with the differential mechanism for driving the traction wheels will enable the truck to be turned completely around within a radius of approximately the length of the truck, thus enabling the truck to be guided around sharp corners.

These and other objects and features of the invention will appear more fully from the following description and the accompanying draw- 3 ings and will be particularly pointed out in the claims.

A preferred embodiment oi the invention is illustrated in the accompanying drawings, in which,

Fig. 1 is a side view, mainly in vertical section, of the front portion of a power driven truck of the fork type showing particularly the power transmitting mechanism for driving the truck, the means for tilting the mast, and the hydraulically operable means for raising and lowering the load supporting means which is mounted upon the mast;

Fig. 2 is an enlarged side view of the truck, portions of the frame and housing being shown in vertical section, and illustrating particularly the mechanism for steering the truck and for controlling the direction and speed at which the truck is driven;

Fig. 3 is an enlarged plan view of the truck with portions of the frame and housing shown in section, illustrating the relative positions of the power unit, the steering mechanism, the power transmitting mechanism for driving the truck, and partially in vertical section hydraulic mechanism for braking the traction wheels of the truck;

Fig. 4 is an enlarged detail illustration mainly in vertical section, viewed laterally, showing the power transmitting mechanism for driving the truck and for continuously actuating the pump for supplying liquid under pressure to the mechanism for tilting the mast and for raising and lowering the load mounted thereon;

Fig. 5 is an enlarged detail view of reversing gear mechanism for driving the truck forwardly or rearwardly at diierent selected speeds;

Fig. 6 is a detail horizontal sectional view on line 6-6 Fig. l, illustrating particularly the manually controlled hydraulic mechanism for tilting the mast and for raising and lowering the load supporting means which is mounted there- Fig. 7 is an enlarged detail horizontal sectional view of the lower end portion of the mast and the ground or door-engaging mast-supporting means which is yieldably mounted therein;

Fig. 8 is an enlarged detail vertical sectional view of the same;

Fig. 9 is a detail vertical sectional view, of one of the steering wheels, on line 9-9 Fig. 2; and.

Fig. 10 is a side elevation of the truck with portions of one of the side plates of the frame broken away to show the construction of the steering wheel mechanism.

The frame, as shown in Figs. 1, 2, 3, and i0, comprises suitably spaced vertical sheet metal side plates i and 2, the lower edge portions of which are connected at their rear ends by a horizontal angle iron girder 3 and an intermediate inverted channel-shaped girder 4 and desirably are provided with upwardly extending arcuate recesses exposing the rear and front wheels of the truck. In the construction illustrated in Fig. 3 parallel beams 5 and 6, which are oiiset inwardly from the plane of the side plates, are connected to the side plates by plates 'l and 8 which are welded to the beams and side plates and are reinforced by triangular webs 9 and I0. An axle housing Il having a reduced portion extends through the iront end portions of the beams 5 and 6 and is secured therein by collars l2 engaging the outer faces of the respective beams 5 and 6. Front traction wheels i3 and Il are mounted respectively on axially alined axles which are journaled in the axle housing Il and actuated through differential gearing of a usual character within a gear box I5 mounted upon and depending from the axle housing Ii intermediate of its width. Suitable means hereinafter described are provided for driving the traction wheel axles.

One of the objects of the invention is to provide novel steering mechanism which in conjunction with the differential mechanism for driving the traction wheels will enable the truck to be guided in a direction forwardly or rearwardly and if desired turned completely around within approximately the length of the truck. This is accomplished by swiveled steering wheels having vertical spindles which are independently mounted upon the vertical side plates of the frame and provided with means for so coordinating rotative movement of the spindles about the respective vertical axes as to cause them to travel in arcuate paths having radii approximately concentric with the tread contact of one of the traction wheels with the iioor.

The steering wheel mechanism, as shown in Figs. 2, 3, 9, and l0, comprises vertical steering wheels i6 having shafts which are journaled in parallel arms Il extending downwardly from a head I8 which is provided with an integral preferably annular extension i9 and with a vertical spindle xedly mounted in and extending upwardly therefrom. The steering wheel mechanism, as particularly shown in Fig. 9, has a central annular recess around the spindle containing ball bearings 2l. A cup-shaped journal 22 is rotatably mounted upon the ball bearing 2| and has an upwardly extending cylindrical wall 23 provided with a bushing surrounding the spindle 20. Suitable brackets 24, which are secured to the opposite side plates i and 2 of the frame, are provided with vertical cylindrical sections 25 which are slidably mounted upon the journals 22 and are provided with upper heads 26 having bushings through which the i5 vertical spindles 20 extend. A heavy coiled spring 2l, which is interposed between the head 26 of the bracket and the journal 22, provides means for permitting the respective steering wheels to yield vertically upwardly when they pass over uneven portions of the iioor and also serves to cushion downward yielding movement of the frame in response to the tipping of the truck by centrifugal displacement as it passes around a sharp curve. Such tipping movement, how- 55 ever, is limited by a cushioned buffer 28 which is mounted upon the extension i9 of the head and is adapted to be engaged by a similar extension 29 upon the cylindrical portion 25 of the bracket 24. Desirably Washers 30 of suitable immaterial are interposed between the upper end of the head 26 and a collar 3i containing a ball bearing which is adjustably secured upon the spindle by a nut 32 engaging threads upon the spindle. The upper end of each spindle, which desirably is of angular construction, has secured to it a rearwardly and outwardly extending arm 33 and as shown in Figs. 3 and 9 the ends of the arms of the respective spindles are connected by a link 34. One of the lateral extensions i9 of the head of the steering wheel is connected by a ball joint 3S to a forwardly extending link 36 the front end 3l of which is similarly secured to the end of an arm 38 f a shaft 39 having means such as a worm gear in engagement with a complementary worm upon the lower end of a steering rod within an upwardly and rearwardly inclined steering post 40 and provided at its upper end with a steering wheel 4|. The connection between the steering post and the link 36 may be of a usual character and detail illustration thereof is unnecessary.

By reason of the construction above described rotation of the steering wheel 4| will act through the link 36 to rotate the vertical spindle of the steering wheel to which the rear end of the link 36 is attached and through the link 34 and arms 33 of the respective spindles so to coordinate the rotation of the spindles about their axes as to guide the truck forwardly or rearwardly, or to turn the truck in any desired direction including abrupt turning of the truck within substantially the length thereof. `The yieldability of the spindle mounting will serve to cushion the frame against jolts which would be produced by irregularities in the surface over which the truck travels and also will cushion abrupt lateral tipping movements of the truck as it passes around sharp curves, thus effectively stabilizing the truck during its transportation.

Another means for assisting in stabilizing the truck comprises novel means for supporting the power unit which is mounted upon the rear portion of the frame.

As illustrated in Figs. 2 and 3 the power unit d2, which may be in the form of an internal combustion engine, electric motor, or otherwise, is mounted upon a base IIIS which is supported at its front end upon suitably spaced resilient members 44 upon the intermediate girder 4 and centrally at its rear end upon a resilient member 45 which is mounted centrally upon a reinforced bracket 46 which underlies and is Welded to the rear girder 3, as shown in Fig. 2, thereby providing a yieldable three-point support for the power unit which will cushion the power unit against shocks which otherwise might be transmitted toit.

The load supporting and lifting means comprises a mast which is mounted upon the front end of the main frame and, as illustrated in Figs. 1, 2, and .3, comprises widely spaced parallel channel bars 41 and 48 facing inwardly having arms 49 a short distance from their lower ends which are fulcrumed on the frame preferably on pivots 50 extending upwardly from the axle housing Il as shown in the lower right hand section of Fig. 3. The load supporting means comprises a carriage having widely spaced rearwardly extending legs 52 and 53 provided with wheels 54 and 55 which travel between the flanges of the respective channel bars 4l and 48 of the mast. The mast is provided with hydraulic lifting mechanism comprising a cylinder 56 which is mounted upon a transverse base plate 51 welded at its ends to the channels of the mast and provided with a ram piston 58 having at its upper end a head which is slidably mounted in the channels and which is connected by suitable means, such as a chain, to the carriage 5| in the usual manner which need not be illustrated herein. Hydraulically operable mechanism is provided for tilting the ram to and from vertical position as will hereinafter be described.

Any suitable means may be provided for carrying the load upon the carriage 5|. In the present construction the load supporting means is in the form of a fork having a plurality of suitably spaced members 59 having at their upper ends reversely shaped hook sections 60 which above the axle of the front wheels the weight.

of the load tends to tip the frame of the truck about said axles and if the load is of sucient weight to raise the rear end of the truck up- Wardly. It is for this reason that usual forms of trucks oi' this character are heavily counter- .weighted at their rear ends.

One oi the important features of the invention is to provide means for so supporting the mast and the load carried thereby as to avoid the necessity of thus heavily counterweighting the rear end of the truck. This is: accomplished in the present invention by providing mast-supporting means adapted when the mast is moved to vertical position to sustain all, or substantially all, of the weight of the load.

In the preferred construction illustrated the lower end of each of the channel bars of the mast has slidably mounted in it a spring loaded bearing 62 such as that shown in Fig. 8 containing a pair of springs 63 with an inverted U-shaped section 64 therebetween adapted to be engaged by the shaft or axle 65 of a roller 66 which is nor mally projected beyond the lower ends of the channel bars of the mast, as shown in Figs. 2 and 10.

The ends of the axle 65 of the roller 66 extend through and slidably fit in vertical recesses 61 in the webs of the channel bars 48 of the mast, the recesses 8l being provided with a lower end wall 68 which will be engaged by the axle 65 to limit the distance which the roller may be projected beyond the lower end of the mast. When the mast 45 is tilted to vertical position the roller 66 will engage the oor and force the bearing members 62 upwardly thereby compressing the springs 63 until the axle engages the arced wall 69 at the upper end of the slot 61 and thereby sustain the 50 weight of the mast and the load supported there- By reason of this construction the fulcrum of the load moment is transferred from the axles of the traction wheels to the bottom of the mast.

55 The total weight of the truck, including the driving wheels and their axles, then act as a counterweight, thus eliminating or reducing the necessity of providing a counterweight upon the rear portion of the frame. In the present construc- 50 tion the fulcrum of the mast is so located that when the mast is tilted rearwardly the desired narrow ground clearance is obtained between the roller and the floor or ground. If during the transportation of the truck brakes are suddenly 05 applied thus causing the truck to tilt forwardly the roller which extends beyond the end of the mast will be brought into contact with the oor and resist such tipping movement. Furthermore, lf the truck is run over an obstruction the spring 70 loaded roller will yield thereby avoiding shock and also preventing the loss of traction of the driving wheels.

By reason of the present construction the following advantages are obtained: (l) the neces- 75 sity of heavily counterweighting the rear portion of the truck is avoided or minimized; (2) easier steering of the truck is accomplished because of the less weight imposed upon the steering wheels which would interfere with their manipulation; (3) better traction will be obtained due to the greater proportion of the total` Weight being imposed upon the traction wheels; (4) better economy in fuel consumption because of reduction of the weight of the truck.

In the practical application of the invention it is found that the desired degree of tilt of the mast from vertical position is about 3 forwardly and 10 rearwardly. The tilting of the mast forwardly is to enable the fingers to be positioned in such proximity to the floor as to enable them to be inserted easily beneath the load and the rearward tilt of 10 will so position the load when properly raised that its center of gravity will be positioned in or slightly rearwardly of the vertical plane of the axis of the traction wheels so that the greater proportion of the weight of the load will be carried by the traction wheels.

Another object of the invention is to provide a truck of the character described with hydraulic mechanism which may be operated to raise the load supporting means when the mast is in vertical loading position, or when tilted rearwardly when the truck is stationary or during its transportation, thereby to position the center of gravity of the load in the most favorable position, and also to provide means for tilting the mast at any time. This is accomplished in the present invention by providing hydraulically operable mechanism mounted upon the front portion of the frame including a pump continuously operated by the power unit so long as the truck is in use and by the provision of means selectively operable by the power unit to drive the traction wheels with manually controlled means for driving the truck forwardly or rearwardly at low or high speeds. The preferred mechanism for accomplishing this purpose comprises a ily wheel 10 which is secured upon the end of a shaft 1| which is continuously driven by the power unit 42 (Figs. l and 4).

The mechanism for driving the pump continuously t supply liquid under pressure to the hydraulic system for raising the load supporting.

means and for tilting the mast comprises a solid horizontal shaft 12 which, as illustrated in Fig. 4, has an angular end portion 13 mounted in a complementary socket in the shaft 1| of the power unit and extends forwardly in axial alinement therewith and is provided at its front end with a gear 14 which meshes with a gear 15 on the shaft of an hydraulic pump 1G the casing of which is bolted to a wall of a gear box 11 of a central frame or housing 18 of irregular contour, as shown in Figs. 2, 3, and 4. The rear end portion .of the housing 18 is mounted upon the intermediate transverse girder 4 and the front end of the housing 18 is secured to the gear box |5 of the axle housing, as shown in Fig. 3. The solid pump actuating shaft 12 is surrounded by and rotatably mounted in a sleeve shaft 19 which is journaled in ball bearings 80 and 8l which are respectively mounted in vertical walls in the housing 18. Manually operable means are provided for releasably connecting the sleeve shaft to the y wheel of the power unit and means are operable by the rotation of the sleeve shaft to drive the front traction wheels of the truck selectively forwardly or rearwardly and at different speeds by mechanism hereinafter described.

The hydraulic system for actuating the hyidraulic ram to raise and lower the load supporting means and to tilt the mast are mounted upon the front portion of the frame and comprises a supply tank B2 from which a pipe 83 leads downwardly to the intake of the pump. A delivery pipe 84 leads from the pump to a cylinder 85 having therein a valve controlled port from which a pipe leads downwardly to the lower portion of the hydraulic lifting cylinder 56 of the ram which is mounted in the mast. A return pipe 81 leads from the cylinder 85 to the supply tank 82 and a constant flow of liquid under pressure is maintained from the pump 1B through the pipe 82, the cylinder 85, and the return pipe 81. The supply of liquid through the pipe 85 to the load lifting cylinder on the mast is controlled by a reciprocating valve 88 which is actuated by a pivotally mounted handle 89 which is located in proximity to the steering column 40 in convenient access to the operator. The liquid supply cylinder 85 also communicates through a pipe 90, as shown in Fig. 6, with the cylinder 9| of a control valve through which liquid under pressure is transmitted to the hydraulic cylinder 02 of masttilting mechanism. The cylinder 92 is pivotally mounted at its rear end upon a shaft 93 upon the superstructure of the frame and is provided with a piston 94 which is connected by a pivot 95 to one of the channel bars 41 of the mast. A ilexible pipe 96, which communicates with the front end portions of the cylinders 9| and 92, provides means for supplying liquid upder pressure to the front chamber of the cylinder 92 to tilt the mast rearwardly, and a similar flexible pipe 91, which communicates with the rear portions of the cylinders 9| and 92, serves to supply uld under pressure to the cylinder 92 to force the piston 94 forwardly to tilt the mast in a forward direction, The cylinder 9| is provided with a piston valve 98 which is operated by a handle 99 in reasonable proximity to the handle 89 which controls the supply of liquid under pressure to the ram cylinder for raising and lowering the load supporting means.

By reason of this construction iiuid under pressure is continuously supplied to the cylinders for actuating the load supporting means and for tilting the mast so that either may be selectively operated at any time to raise and lower the load supporting means or to .tilt the mast.

It has heretofore been pointed out that the mechanism for driving the traction wheels is actuated by a tubular sleeve shaft 19 which surrounds and is rotatably mounted upon the solid shaft 12 which actuates the pump. The preferred mechanism illustrated in Figs. 1 and 4 comprises a clutch mechanism upon the rear end of the tubular shaft which is adapted releasably to engage the face of the y wheel 10. This clutch mechanism, as shown in Fig. 4, is in the form of a spider having a hub |00 provided with internal teeth which slidably engage complementary grooves |0| extending longitudinally of the rear end portion of the sleeve shaft 19. The rear peripheral face of the spider has secured to it a brake lining |02 which engages a disk |03 which is interposed between it and a complementary brake lining |00 which is xedly secured to the hub. A plurality of equally spaced spiral springs |05, one of which is shown, are interposed between the peripheral portion of the spider and parallel oiset portions |06 of a resilient disk-like plate |01 having a reversely oiset portion |08 which normally maintains the brake linings |02 and |04 in light contact with the disk |03 therebetween.

Suitable means are provided for forcing the clutch members into driving contact. As illustrated in Fig. 4 a boss |09. which projects forwardly from the lower portion of the periphery of the spider, has pivotally secured to it a lever provided with a convexedly curved end portion which engages a rear ball race I I2 of an annular ball bearing which is mounted in the collar H3 which is slidably mounted upon a sleeve ||4 which surrounds the sleeve shaft 19. The collar H3 is provided with diametrically opposite studs I5 which are engaged by the forkshaped upper ends of arms I I6 the lower ends of which are mounted upon a sleeve ||1 which is keyed to a shaft ||8. The lever I I0 is provided intermediate of its length with an adjusting screw 9 which engages the plate |01. The shaft ||8 has secured to its end a forwardly extending arm |20 (Figs. 2 and 3), the front end of which is pivotally secured to an upwardly extending link 2| the upper end of which is pivotally secured to the arm |22 of a bell crank pedal lever |23 having at its end a clutch actuating pedal |24 which is positioned in convenient proximity to the steering post 40 in convenient reach of the operator.

The mechanism for transmitting power from the sleeve shaft 19 to the front traction wheels comprises an enlarged longitudinally grooved forward toothed section |25 of the sleeve shaft 19 upon which is slidably mounted a gear |26 adapted to mesh with a large gear |21 which is fixedly secured upon a countershaft |28 which is mounted in antifriction bearings |29 and |30 respectively in front and rear vertical walls of the housing 18. The shaft |28 also has fixedly mounted upon it in front of and in parallelism with the gear |21 another gear 3| of smaller diameter and the gear |26 is adapted when moved forwardly to engage a gear |32 which meshes with the gear |3| thereby to drive the shaft |28 in the reverse direction. Suitable means are provided for sliding the gear |26 upon the grooved portion |25 of the sleeve shaft selectively into engagement with the gear |21 or lthe gear |3| which as illustrated herein com-y prises a fork |33 having a laterally extending arm |34, as indicated in Fig. 5, which is secured to a shaft |35 slidably movable in bearings upon the housing 18 and which is connected at its end to the arm of a shaft |36 the opposite end of which is provided with an arm |31 the upper end of which is connected by a link |38 to an arm |39 which is xedly mounted upon a vertical shaft |40 which extends upwardly in parallelism with the steering post and is provided at its upper end with a handle |4I. By rotating the handle |4| in a proper direction the gear |28 will slide upon the grooved section |25 of the sleeveshaft to place the gear i 25 in engagement with the gear |21 to drive the truck in a forward direction or by rotating the handle |4| in the opposite direction to cause engagement of the gear |26 with the intermediate gear |32, thereby to drive the gear |3| and thereby propel the truck in the reverse direction.

Suitable means are also provided for selectively driving the traction wheels at different speeds either in forward or reverse direction. As shown in Fig. 4 the shaft |28 is provided at its front end with a gear |42 which is adapted to mesh with the teeth of a gear |43 the hub of which is slidably mounted upon longitudinally grooved teeth of another countershaft |44. The hub of the gear |43 is provided with teeth forming another gear |45 of smaller diameter which is adapted to mesh with the gear |3| on the countershaft |28. Suitable means are provided for sliding the gear |48 lengthwise upon the 5 shaft |44. This is shown diagrammatically in Fig. 4 and comprises a fork |46 on the hub of the gear |48 which is connected at its end to a shaft |41 which is slidably mounted in bearings in the housing and is pivotally connected at its forward end to an arm |48 upon a shaft |49, the opposite end of which has an arm |50 which is pivotally connected to a link |5I the other end of which is connected to an arm |52 upon the lower end of a rod |53 which extends upwardly in parallelism with the steering post and is provided at its upper end with a handle |54. By rotating the handle |54 in the proper direction the gear |43 will be placed in mesh with the gear |42, thereby to drive the shaft |44 at a low speed and when moved in the opposite direction will cause the gear |46 to mesh with the gear I3| and drive the shaft |44 at a relatively slow speed.

The shaft |44 has secured to its end a beveled gear |55 which meshes with both of the gears |56 of the differential mechanism for driving the traction wheels. By proper manipulation of the handles |4| and |54 the truck may therefore be driven in a forward or reverse direction /at either a high speed or low speed as desired.

Suitable means are provided for positively and eiectively braking the forward or rearward movement of the truck. Hydraulically operable brakes are applied directly to both of the traction wheels. One of such braking mechanisms is illustrated in Fig. 3 as applied to one of the traction wheels I3 and a like mechanism not illustrated is applied to the other traction wheel I4. As illustrated a brake controlling cylinder |51 is bolted at one end -to the offset portion 1 of the forwardly extending beam 5 and is filled with liquid in the usual manner. A pipe |58 leads from the chamber of the cylinder to a supplemental brake actuating cylinder |59 which is mounted upon the axle housing and is provided with oppositely extending pistons |60 having oppositelyextending links |6| which are pivotally connected to the upper ends of webs |82 integral with brake shoes |63 which engage the inner flange |64 of the traction wheels. The brake shoes |63 are pivotally mounted at their lower ends upon studs |65 and |66 on the I axle housing and are normally held from engagement with the ange of the wheel by a tension spring |51 which connects the lower end portions of the brake shoes at a suitable distance above the pivots thereof. When it is desired to apply the brake shoes liquid under pressure is supplied from the cylinder |51 through the pipe |58 to the brake actuating cylinder |59 thereby to spread apart the upper ends of the brake shoes and force them into engagement with the flange |64 of the traction wheels. This is accomplished by providin-g the brake controlling cylinder |51 with a piston |68 having a piston rod |69 which is 'pivotally connected to the lower end of a vertical lever |10 the upper 70 end of which, not shown, is connected by a link |1| to the lower arm |12 of a bell crank lever which is pivotally mounted upon the frame with its other arm |13 connected by a link |14 to the forwardly extending arm |15 oi' a bell crank lever which is mounted upon the shaft I22z,

which forms a fulcrum of the clutch lever, and is provided with a downwardly and upwardly extending curved arm similar to that of the clutch lever and is positioned in parallelism therewith in proximity to the steering post and provided with a pedal similar to and in parallelism with the clutch pedal |24.

The front end of the truck is provided with a sheet metal hood |18 which encloses the hydraulically operated mechanism for tilting the mast, the controlling mechanism therefor; and the lever and link mechanisms for controlling the hydraulically operable means for actuating the load supporting means, and the lever mechanisms for actuating the clutch and brake above described.

The truck is mounted upon the side frames adjacent the steering handle and a plate |11 which overlies the housing containing the power transmission mechanism and forms a floor for the feet of the operator. It also comprises a vertical plate section |18 which extends upwardly from the licor to the upper ends of the side plates i and 2 of the frame. A sheet metal cab |19, which is detachably mounted upon the upper edges of the side frames, overlies the power unit and steering mechanism and desirably is provided at its front end with a seat |80 for the operator which may if desired have a back |8| as shown in Fig. 10.

By reason of this construction the operator may during the manipulation of the truck sit upon the seat |88 with the steering wheels, the handles controlling the mechanisms for driving the truck at full or low speed and for reversing the direction of the truck within easy reach of his hand. The clutch controlling pedal and the brake pedal are in the present construction positioned above the floor on which the feet of the operator rests and therefore are easily accessible for manipulation by the operators foot or feet to operate the clutch and to apply the' brake. This is also believed to be a novel feature and facilitate the operation and control of the truck.

If necessary or desirable a counterweight |82 may be detachably mounted upon the rear girder 3 of the truck, as shown in Figs 2, 3, and 10. In view of the stabilizing mechanism heretofore described relatively light counterweights may be employed. The counterweight |82 may be provided with a large aperture |83 adapted to admit air to a radiator |84 of the power unit which is located in front of the usual fan |85 which is mounted upon an extension of the shaft |86 of the power unit. The shaft |86 may be provided with a pulley |81 which drives a pulley |88 upon an electric generator |89 which is mounted upon the power unit and which generates a current adapted to supply a usual storage battery, not shown, from which the current may be supplied to a starter motor |90 of the Bendix type suitably mounted upon the housing 18 and provided with a driving gear adapted to engagethe teeth ISI on the periphery of the ily wheel 10.

In the operation of the truck embodying the invention, the truck is driven forwardly in proximity to the load, which is usually mounted upon a pallet. The mast is then tilted forwardly to enable the fingers 6| of the load supporting means properly to enter the pallet upon further forward movement of the truck. Fluid' under pressure is then supplied to the hydraulic cylinder 56 of the mast which causes the ram 58 thereof to raise the load supporting means with the load upon it, the mast at this time being in approximately vertical position so that the weight of the load is carried by the roller which is mounted upon the foot of the mast, thus stabilizing the truck against being tipped forwardly by the weight of the load. The mast-tilting mechanism is then actuated to tilt the mast rearwardly to position the weight of the load above or slightly rearwardly of the vertical plane of the axes of the traction wheels. As the mast is thus tilted rearwardly the springs 83 extend the roller 66 a short distance beyond the foot of the mast and narrowly out of contact with the floor so that when the truck is driven to transport the load the roller 66 will engage any irregularity or obstruction in the path of the truck, will assume such weight of the load as will prevent loss of traction of the driving wheels, or if the brake is suddenly applied during the travel of the truck the roller will be brought into contact with the iloor and thereby prevent forward tipping of the truck. The mast-supporting means thereby cooperates with the yieldable steering wheel mechanism and the resilient supports for the power unit to stabilize the loaded truck during its transportation.

When the truck reaches its destination the mast is again tilted to vertical position by the hydraulic mechanism above described thereby again causing the mast-supporting means to prevent tipping of the truck forwardly about the axes of the traction wheels during the lowering or raising and lowering of the load supporting means to deposit the load.

By reason of the construction above described the necessity for a heavy counterweight upon the rear of the truck is avoided and a large reduction in the total Weight of the truck permitted which results in easier steering of the truck due to the less weight imposed on the steering wheels. Furthermore, better traction is provided because of the total weight of the truck being imposed upon the traction wheels and the reduction in the total weight of the truck naturally results in a greater fuel economy.

By reason of the means for continuously operating the pump, the tilting of the mast, and the operation of the hydraulic mechanism for raising and lowering the load supporting means, the Weight of the load may be positioned at any time during the transportation of the truck most advantageously to position it relatively to the vertical axes of the traction wheels, and by reason of the yielding supports for the steering wheels and the resilient supports for the power unit abrupt shocks due to the centrifugal force applied to the load as the truck passes around abrupt turns in the path of the truck are cushioned and lateral displacement of the load thereby prevented. By the assemblage all mechanisms for controlling the operation of the truck are concentrated within easy reach of the feet or hands of the operator while seated upon the cab. The operation of the trck can then be conveniently controlled by him at all times.

It will be understood that the particular embodiments of the invention shown and described herein are of an illustrative character and are not restrictive of the meaning and scope of the following claims.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

1. A stabilized load lifting power actuated truck having a main frame comprising vertical parallelrigid side plates of suitable thickness connected at their lower portions by a rear and an inter- 2,494, nos

mediate girder, means including an axle housing connecting the front ends of said side plates, traction wheels having alined axles journaled in said axle housing, a pair of swiveled rear steering wheels having vertical spindles yieldably journaled in brackets mounted on said side plates, means including an upwardly extending steering post mounted in the front portion of said frame having a steering handle, means operable thereby to rotate said spindles to guide the truck capable in conjunction with the differentially driven traction wheels to turn the truck within approximately its length, a mast fulcrumed on the front portion of said main frame to tilt to and from a vertical position in front of and spaced from the vertical plane of the axis of the traction wheels, load supporting means mounted upon and movable lengthwise of the mast, mast-supporting rollers mounted on the foot of said mast movable upon erection of said mast into engagement with the floor and operable in cooperation with the yieldable steering wheels to stabilize the truck during loading and unloading of the truck and during the transportation thereof, a platform yieldably mounted on said rear and intermediate girders, a power unit mounted thereon, and means respectively operable thereby to actuate said traction wheels, the means for the tilting of the mast and the load supporting means.

2. A stabilized load lifting power actuated truck comprising an integral fabricated main frame having widely spaced vertical rigid side plates connected at their lower edge portions by a rear and an -intermediate girder, means including an axle housing connecting the front ends of said side plates, traction wheels having alined axles journaled in bearings in said housing, diierential mechanism in said housing connecting said axles, a pair of rear steering wheels having vertical spindles journaled in brackets mounted respectively on the rear portions of said side plates, each having a coiled spring surrounding its spindle, manually controlled means for actuating said spindles to guide the truck, a mast fulcrumed on the frame to tilt to and from a vertical position in front of and spaced from the vertical plane of the axis of the traction wheels hailing mast-supporting means to engage the oor when the mast is erected to vertical position, load supporting means mounted on the mast and means for raising and lowering the load supporting means, a platform mounted on three-point resilient supports upon said rear and intermediate girders, a power unit mounted upon said platform exending longitudinally of said main frame, and manually controlled means operable thereby respectively to actuate said traction wheels to drive the truck to raise and lower the load supporting means and to move the mast to and from said vertical position.

3. A stabilized load lifting power actuated truck comprising an integral fabricated main frame having widely spaced vertical rigid side plates connected at their lower edge portions by a rear and an intermediate girder, means including an axle housing connecting the front ends of said side plates, traction wheels'having alined axles journaled in bearings in said housing, diierential mechanism in said housing connecting said axles, a pair of rear steering wheels each having a bifurcated head with a wheel mounted therein and a vertical spindle journaled in a bracket mounted on the rear portion of a side plate, a coiled spring surrounding each spindle interposed between its head and the bracket,` a flange on the bracket and a resilient buffer on said head cooperating therewith to limit the extent oi yielding movement of the steering wheel, arms connected to the upper ends of the respective spindles, means connecting said arms to coordinate the rotary movements thereof, and manually controlled means for actuating the steering wheels to guide the truck, a mast fulcrumed on the frame to tilt to and from a vertical position in front of and spaced from the vertical plane of the axes of the traction Wheels having a mast-supporting roller yieldably mounted upon the lower end thereof to engage the floor when the mast is erected to vertical position, to prevent the truck from tilting forwardly by the weight of a heavy load when applied to the mast and adapted to be extended beyond the lower end of said mast when it is tilted rearwardly thereby to engage irregularities in the surface of the floor during the transportation of the truck and' to cooperate with said resiliently mounted steering wheels in stabilizing the truck.

4. A stabilized load lifting power actuated truck comprising an integral fabricated main frame' having widely spaced vertical rigid side plates connected at their lower edge portions by a rear and an intermediate girder, means including an axle housing connecting the front ends of said side plates, traction wheels having alined axles journaled in bearings in said housing, differential mechanism in said housing connecting said axles, a pair of rear steering wheels having vertical spindles journaled in brackets mounted respectively on the rear portions of said side plates, means for actuating the steering wheels to guide the truck, a housing extending centrally longitudinally of the truck mounted respectively on the said intermediate girder and said axle housing, a power unit having a driving shaft mounted upon said rear and intermediate girders having a horizontal driving shaft in alinement with said housing, a solid shaft connected to the front end of said driving shaft, a sleeve shaft rotatably mounted upon said solid shaft journaled in antifriction bearings in said housing having clutch mechanism for connecting it to said driving shaft, a mast fulcrumed on the front end of said main frame to tilt to and from a vertical position, load supporting means mounted on said mast movable lengthwise thereof, an hydraulic system for raising and lowering said load supporting means and for tilting said mast comprising a pump mounted upon the front end of said housing, means operable by said solid shaft for continuously driving said pump, manually controlled means respectively operable to supply liquid under pressure from said pump to the hydraulically operated load supporting means and to the masttilting means, and a train of gearing in said hous; ing operable by said sleeve shaft to drive said differential mechanism and thereby to actuate the traction wheels.

5. A stabilized load lifting power actuated truck comprising an integral fabricated main frame having widely spaced vertical rigid side plates connected at their lower edge portions by a rear and an intermediate girder, means including an axle housing connecting the front ends of said side plates, traction wheels having alined axles journaled in bearings in said housng, diierential mechanism in said housing connecting said axles, a pair of rear steering wheels having vertical spindles journaled in brackets mounted respectively on the rear portions of said side plates,

means for actuating the steering wheels to guide the truck, a housing extending centrally longitudinally of the truck mounted respectively on the said intermediate girder and said axle housing, a power unit having a yieldable base` mounted upon said rear and intermediate girders and having a horizontal driving shaft in alinement with said housing, a solid shaft connected to the front end of said driving shaft, a sleeve shaft rotatably mounted upon said solid shaft journaled in antifriction bearings in said housing having clutch mechanism for connecting it to said driving shaft, a mast fulcrumed on the front end of said main frame to tilt to and from a vertical position, load supporting means mounted on said mast movable lengthwise thereof, an hydraulic system for raising and lowering said load supporting means and for tilting said mast comprising a pump mounted upon the front end of said housing, 'means operable by said solid shaft for continuously driving said pump, manually controlled means respectively operable to supply liquid under pressure from said pump to the hydraulically operated load supporting means and to the mast-tilting means, and a train of gearing in said housing operable by said sleeve shaft to drive said differential mechanism and thereby to actuate the traction wheels including manually operable gear-shifting means within said housing to drive the traction wheels at different speeds and in forward or rearward directions.

6. A power actuated load lifting truck comprising a main frame having vertical wide fiat side plates, rear and intermediate girders connecting the lower edge portions of the side plates, means including an axle housing connecting the front ends of said side plates, traction wheels having alined axles mounted in said axle housing connected by differential mechanism, a pair of swiveled rear steering wheels, means for actuating said steering wheel to guide the truck including an upwardly extending steering post mounted in the front end of the frame and having a steering handle, a power unit mounted on the rear portion of said frame, a cab enclosing the power unit and rear steering wheels having a removable cover provided with a seat detachably connected to the side plates, a floor between the cab and the steering post, a mast fulcrumed on the frame to tilt to and from a vertical position in front of and spaced from the vertical plane of the axes of the traction wheels, load supporting means mounted on the mast, an

hydraulic system comprising hydraulically actuated means respectively operable to raise and lower the load supporting means and to tilt the mast, a pump actuated by said power unit continuously to supply fluid under pressure to said hydraulic system, valve mechanism located in close proximity to said steering post, having handles within convenient reach of the operator operable to control the flow of :duid under pressure respectively to the hydraulic mechanism for raising and lowering the load supporting means and to the hydraulic mechanism for tilting the mast.

'7, A load lifting power actuated truck having a main frame comprising parallel side plates connected at their lower edge portions by rear and steering wheels mountedv respectively on said side plates, and means for actuating the same to guide the truck including an upwardly extending steering post mounted on the front end of the frame and provided with a steering handle, a power unit mounted upon the central rear portion of the frame having a continuously rotating drivlng shaft extending lengthwise of the frame, a gear housing mounted on said intermediate girder and said axle housing in alinenent with said driving shaft having a pump mounted on the front end thereof, a pump actuating shaft flxedly connected to said driving shaft in axial alinement therewith, gearing connecting said pump to the pump actuating shaft, a sleeve shaft rotatably fitting said pump driving shaft journaled in antifriction bearings in said housing, a clutch releasably connecting the sleeve shaft to the driving shaft, trains of gearing in said gear housing operable by the rotation of said sleeve shaft to drive the traction wheels including the gear shifting mechanism respectively operable to drive the truck forwardly or rearwardly selectively at diierent speeds, and controlling means therefor having manually operable members located in proximity to the steering post.

8. A load lifting power actuated truck having a main frame comprising parallel `side plates connected at their lower edge portions by rear and intermediate girders and at their front ends by means including an axle housing, traction wheels having axially alined axles mounted in said axle housing and connected by differential gearing centrally within said axle housing, a pair of rear steering wheels mounted respectively on said side plates, and means for actuating the same to guide the truck including an upwardly extending steering post mounted on the front end of the frame and provided with a steering handle, a power unit mounted upon the central rear portion of the 'frame having a continuously rotating driving shaft; extending lengthwise of the frame, a gear housing mounted on said intermediate girder and said axle housing in alinement with said driving shaft having a pump mounted on the front end thereof, a pump actuating shaft fixedly connected to said driving shaft in axial alinement therewith, gearing connecting said pump to the pump actuating shaft, a 'mast fulcrumed on the front end of said frame to tilt to and from a vertical position in front of and spaced from the vertical plane of the axis of the steering wheel, load supporting means mounted on and movable lengthwise of the mast, an hydraulic system for actuating the load supporting means and means for tilting the mast including a reservoir mounted on the front portion of the frame for supplying liquid to the pump, and manually operable valve actuating means having handles located in proximity to the steering post in con- 4 venient reach of the operator respectively operintermediate girders and at their front ends by means including an axle housing, traction wheels having axially alined bearings mounted in said axle housing connected by differential gearing centrally within said axle housing, a pair of rear able to control the supply of iiuid under pressure to the means for raising and lowering the load supporting means and to the means for tilting the mast.

9. A stabilized load lifting power actuated truck having a main frame provided at its front end with widely spaced axially alined traction wheels and having a pair of widely spaced swiveled rear steering wheels each having a head with a vertical spindle journaled in a bearing upon the frame and having a coiled spring surrounding its spindle interposed between said head and bearing, a mast fulcrumed on the main frame to tilt to and from 17 a vertical position in front of and spaced from the vertical plane of the axes of said traction wheel axles, mast-supporting means comprising a roller journaled in bearings slidably mounted in the lower end portions of said mast members, springs acting upon said bearings normally to extend the roller a limited distance beyond the ends of said mast members when the mast is in tilted position, means for tilting said mast to vertical position to cause said rollers upon engagement with the iioor thereby to move said bearings against the force of said springs and to support the weight of the mast and the load carried thereby and operable to preventl forward tipping of the truck, said roller being operable when extended beyond the foot of the mast when .it is tilted rearwardly for transportation to engage irregularities in the path of the truck and in cooperation with the yielding steering Wheels to stabilize the truck during the transportation thereof.

10. A power actuated fluid lifting truck having a main frame comprising wide vertical flat side plates connected at their lower edges by a horizontal rear girder and an intermediate girder and at their front ends by means including an axle housing, traction wheels having axially alined axles journaled in said housing and connected by differential gearing, braking means for the respective traction wheels, swiveled rear steering wheels having vertical spindles mounted on the respective side plates, and means for actuating the same to guide the truck including an upwardly extending steering post mounted upon the front end portion of the main frame, a mast mounted on the iront portion of the main frame, load supporting means mounted upon and movable longitudinally of said mast, means for raising and lowering the load supporting means, and controlling means therefor mounted on the front portion of said frame in proximity to said steering post, a power unit mounted on the rear portion of said frame having a horizontal driving shaft extending longitudinally thereof, a power transmitting shaft in axial alinement with said driving shaft, a clutch for releasably connecting the power transmitting shaft to the driving shaft, means operable by said driving shaft to actuate the traction wheels, a. cover mounted on said side plates providing therewith a cab enclosing said power unit and the steering wheels and provided with a seat for the operator, a iioor mounted on said side plates between the cab and the steering post, means respectively for actuating said clutch, braking means each comprising a bell crank level-fulcrumed upon the frame in front of the steering post and well above the plane of said oor, each having an arm extending downwardly from its fulcrum and rearwardly over seid floor in proximity to the steering post and provided at its end with a pedal in easy reach of the operator when seated upon said cab.

11.` A power actuated load lifting truck having a main frame comprising wide vertical fiat plates connected at their lower edges by a horizontal rear girder and an intermediate girder and at their front ends by means including an axle housing, traction wheels having axially alined axles journaled in said axle housing connected by diierential gearing, hydraulic braking means for the respective traction Wheels, swiveled rear steering wheels having vertical spindles mounted on the respective side plates, and means for actuating the same to guide the truck including an upwardly extending steering post mounted on the front end portion of the main frame, a mast fulcrumed on said frame to tilt to and from a vertical position, load supporting means mounted on said mast and movable lengthwise thereof, hydraulically operable means for raising and lowering said load supporting means, and hudraulically operable means for tilting the mast having controlling means located in proximity to the steering post, a power unit mounted on the rear portion of the frame having a horizontal driving shaft extending longitudinally of the frame, a power transmitting shaft in axial aiinement with the driving shaft, and means operable thereby to drive the traction wheels, a clutch for releasably connecting the power transmitting shaft to said driving shaft, a cover mounted on said side plates providing a cab enclosing said power unit and steering wheels and provided with a seat for the operator, a oor mounted on said side plates between the cab and steering post, means for respectively actuating the clutch and brake mechanism each comprising a bell crank lever fulcrumed on the frame in front of the steering post and well above the plane of said floor and having an arm extending downwardly from its fulcrum and rearwardly over said oor in proximity to the steering post and provided with a pedal Within easy reach of the foot of the operator when seated on said cab. a hood mounted on the front portion of said frame enclosing said bell crank levers and the means for controlling the driving of the truck, the tilting of the mast, and the raising and lowering of the load supporting means within convenient reach of the operator while seated upon said cab.

CHARLES S. BOUCHARD.

' REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Anthony Feb. 6, 1940 

